# Copyright (C) 2011, 2012 Nippon Telegraph and Telephone Corporation.
# Copyright (C) 2011, 2012 Isaku Yamahata <yamahata at valinux co jp>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import contextlib
import gflags
import logging
import gevent
import traceback
import random
import greenlet
from gevent.server import StreamServer
from gevent.queue import Queue
from ryu.ofproto import ofproto
from ryu.ofproto import ofproto_parser
from ryu.ofproto import ofproto_v1_0
from ryu.ofproto import ofproto_v1_0_parser
from ryu.ofproto import ofproto_v1_2
from ryu.ofproto import ofproto_v1_2_parser
from ryu.ofproto import nx_match
from ryu.controller import dispatcher
from ryu.controller import handler
from ryu.controller import ofp_event
LOG = logging.getLogger('ryu.controller.controller')
FLAGS = gflags.FLAGS
gflags.DEFINE_string('ofp_listen_host', '', 'openflow listen host')
gflags.DEFINE_integer('ofp_tcp_listen_port', ofproto.OFP_TCP_PORT,
'openflow tcp listen port')
class OpenFlowController(object):
def __init__(self):
super(OpenFlowController, self).__init__()
# entry point
def __call__(self):
#LOG.debug('call')
self.server_loop()
def server_loop(self):
server = StreamServer((FLAGS.ofp_listen_host,
FLAGS.ofp_tcp_listen_port),
datapath_connection_factory)
#LOG.debug('loop')
server.serve_forever()
def _deactivate(method):
def deactivate(self):
try:
method(self)
except greenlet.GreenletExit:
pass
except:
traceback.print_stack()
raise
finally:
self.is_active = False
return deactivate
class Datapath(object):
supported_ofp_version = {
ofproto_v1_0.OFP_VERSION: (ofproto_v1_0,
ofproto_v1_0_parser),
ofproto_v1_2.OFP_VERSION: (ofproto_v1_2,
ofproto_v1_2_parser),
}
def __init__(self, socket, address):
super(Datapath, self).__init__()
self.socket = socket
self.address = address
self.is_active = True
# The limit is arbitrary. We need to limit queue size to
# prevent it from eating memory up
self.send_q = Queue(16)
# circular reference self.ev_q.aux == self
self.ev_q = dispatcher.EventQueue(handler.QUEUE_NAME_OFP_MSG,
handler.HANDSHAKE_DISPATCHER,
self)
self.set_version(max(self.supported_ofp_version))
self.xid = random.randint(0, self.ofproto.MAX_XID)
self.id = None # datapath_id is unknown yet
self.ports = None
self.flow_format = ofproto_v1_0.NXFF_OPENFLOW10
def close(self):
"""
Call this before discarding this datapath object
The circular refernce as self.ev_q.aux == self must be broken.
"""
# tell this datapath is dead
self.ev_q.set_dispatcher(handler.DEAD_DISPATCHER)
self.ev_q.close()
def set_version(self, version):
assert version in self.supported_ofp_version
self.ofproto, self.ofproto_parser = self.supported_ofp_version[version]
# Low level socket handling layer
@_deactivate
def _recv_loop(self):
buf = bytearray()
required_len = ofproto.OFP_HEADER_SIZE
count = 0
while self.is_active:
ret = self.socket.recv(required_len)
if len(ret) == 0:
self.is_active = False
break
buf += ret
while len(buf) >= required_len:
(version, msg_type, msg_len, xid) = ofproto_parser.header(buf)
required_len = msg_len
if len(buf) < required_len:
break
msg = ofproto_parser.msg(self,
version, msg_type, msg_len, xid, buf)
#LOG.debug('queue msg %s cls %s', msg, msg.__class__)
self.ev_q.queue(ofp_event.ofp_msg_to_ev(msg))
buf = buf[required_len:]
required_len = ofproto.OFP_HEADER_SIZE
# We need to schedule other greenlets. Otherwise, ryu
# can't accept new switches or handle the existing
# switches. The limit is arbitrary. We need the better
# approach in the future.
count += 1
if count > 2048:
count = 0
gevent.sleep(0)
@_deactivate
def _send_loop(self):
while self.is_active:
buf = self.send_q.get()
self.socket.sendall(buf)
def send(self, buf):
self.send_q.put(buf)
def set_xid(self, msg):
self.xid += 1
self.xid &= self.ofproto.MAX_XID
msg.set_xid(self.xid)
return self.xid
def send_msg(self, msg):
assert isinstance(msg, self.ofproto_parser.MsgBase)
if msg.xid is None:
self.set_xid(msg)
msg.serialize()
# LOG.debug('send_msg %s', msg)
self.send(msg.buf)
def serve(self):
send_thr = gevent.spawn(self._send_loop)
# send hello message immediately
hello = self.ofproto_parser.OFPHello(self)
self.send_msg(hello)
try:
self._recv_loop()
finally:
gevent.kill(send_thr)
gevent.joinall([send_thr])
def send_ev(self, ev):
#LOG.debug('send_ev %s', ev)
self.ev_q.queue(ev)
#
# Utility methods for convenience
#
def send_packet_out(self, buffer_id=0xffffffff, in_port=None,
actions=None, data=None):
if in_port is None:
in_port = self.ofproto.OFPP_NONE
packet_out = self.ofproto_parser.OFPPacketOut(
self, buffer_id, in_port, actions, data)
self.send_msg(packet_out)
def send_flow_mod(self, rule, cookie, command, idle_timeout, hard_timeout,
priority, buffer_id=0xffffffff,
out_port=None, flags=0, actions=None):
if out_port is None:
out_port = self.ofproto.OFPP_NONE
flow_format = rule.flow_format()
assert (flow_format == ofproto_v1_0.NXFF_OPENFLOW10 or
flow_format == ofproto_v1_0.NXFF_NXM)
if self.flow_format < flow_format:
self.send_nxt_set_flow_format(flow_format)
if flow_format == ofproto_v1_0.NXFF_OPENFLOW10:
match_tuple = rule.match_tuple()
match = self.ofproto_parser.OFPMatch(*match_tuple)
flow_mod = self.ofproto_parser.OFPFlowMod(
self, match, cookie, command, idle_timeout, hard_timeout,
priority, buffer_id, out_port, flags, actions)
else:
flow_mod = self.ofproto_parser.NXTFlowMod(
self, cookie, command, idle_timeout, hard_timeout,
priority, buffer_id, out_port, flags, rule, actions)
self.send_msg(flow_mod)
def send_flow_del(self, rule, cookie, out_port=None):
self.send_flow_mod(rule=rule, cookie=cookie,
command=self.ofproto.OFPFC_DELETE,
idle_timeout=0, hard_timeout=0, priority=0,
out_port=out_port)
def send_delete_all_flows(self):
rule = nx_match.ClsRule()
self.send_flow_mod(
rule=rule, cookie=0, command=self.ofproto.OFPFC_DELETE,
idle_timeout=0, hard_timeout=0, priority=0, buffer_id=0,
out_port=self.ofproto.OFPP_NONE, flags=0, actions=None)
def send_barrier(self):
barrier_request = self.ofproto_parser.OFPBarrierRequest(self)
self.send_msg(barrier_request)
def send_nxt_set_flow_format(self, flow_format):
assert (flow_format == ofproto_v1_0.NXFF_OPENFLOW10 or
flow_format == ofproto_v1_0.NXFF_NXM)
if self.flow_format == flow_format:
# Nothing to do
return
self.flow_format = flow_format
set_format = self.ofproto_parser.NXTSetFlowFormat(self, flow_format)
# FIXME: If NXT_SET_FLOW_FORMAT or NXFF_NXM is not supported by
# the switch then an error message will be received. It may be
# handled by setting self.flow_format to
# ofproto_v1_0.NXFF_OPENFLOW10 but currently isn't.
self.send_msg(set_format)
self.send_barrier()
def datapath_connection_factory(socket, address):
LOG.debug('connected socket:%s address:%s', socket, address)
with contextlib.closing(Datapath(socket, address)) as datapath:
try:
datapath.serve()
except:
# Something went wrong.
# Especially malicious switch can send malformed packet,
# the parser raise exception.
# Can we do anything more graceful?
LOG.error("Error in the datapath %s from %s",
datapath.id, address)
raise